VIA PT894 & PT880 Pro Chipset Preview

Introduction and PT894 Specifications


VIA is perhaps most notable for its contributions as a supplier of chipsets for AMD's Athlon XP/64 processor families. The company's work with Intel's offerings has ranged, over time, from clandestine manufacturing of unlicensed core logic (in Intel's eyes, at least) to the manufacture of a respectably leading edge product in the form of its PT880.

Up until now, however, all of VIA's products have featured AGP graphics connectivity and it doesn't take a gifted mind to realize that the industry is trudging forward with PCI Express. So, while all of its competitors have already made that pivotal transition on the AMD side, VIA is now unveiling its family of Pentium 4 chipsets with PCI Express support.

The move is significant for a couple of major reasons. Not only does it allow VIA to compete against Intel, one-upping whatever plans NVIDIA and ATI might have to contend for Pentium 4 chipset supremacy, but it also represents the first chipset family outside of NVIDIA's nForce4 SLI to officially support multiple display adapters, adding appeal to the Pentium 4 in financial and content creation markets.

Specifications Of The VIA PT894 Chipset
VIA's Proactive Move for P4
Support for Intel Pentium 4 processors on 533, 800, and 1066 MHz front side buses, including the upcoming 6xx series.

20 Lanes of PCI Express Connectivity
_PT894 north bridge includes one x16 link for graphics and two x1 links for peripheral connectivity
_VT8251 south bridge adds two more x1 lanes for attaching peripherals

VIA StepUp Technology
_Flexible memory architecture supports DDR/DDR2 memory
_DDR 266/333/400
_DDR2 400/533/667

VIA Ultra V-Link
_Proprietary interconnect between north and south bridges transferring up to 1 GBps of data

VIA Vinyl Audio
_Compliance with HD Audio standard
·_Stylus audio drive with QSound technology and Immerzio gaming support
·_Six-channel audio through VIA Six-TRAC AC'97 codec
·_Eight-channel audio through VIA Envy24PT PCI controller
VIA DriveStation
_3Gbps with VT8251 south bridge
_RAID 0, 1, 0+1, and 5
·_Management through V-RAID software interface
·_Port multiplier support
·_RAID morphing, disk alert, spare disk allocation

VIA Connectivity
_Fast 10/100 Ethernet
_Eight USB 2.0 ports
·_Standard PCI bus


PT894, the mid-range offering in VIA's three-member PCIe lineup, looks very similar to previous VIA products, at least from a block-diagram perspective. However, notice that the PT894 north bridge offers one x16 link and a pair of x1 lanes for peripheral connectivity. It also supports Pentium 4 processors with 1066 MHz front side bus speeds - a relevant improvement over Intel's 925X, which officially tops out at 800 MHz. Then, there's memory support. From VIA's point of view, DDR2 hasn't seen widespread adoption quite yet, justifying support of both DDR and DDR2 memory technologies. The PT894 supports DDR at 266, 333, and 400 MHz, in addition to DDR2 at 400, 533, and 667 MHz (DDR2 667 isn't listed in the block diagram; VIA still claims support in its press material).

Moving down the hierarchy, PT894 connects to a south bridge - either VT8237 or VT8251 - through Ultra V-Link, a proprietary bus interconnect capable of transferring more than 1 GBps. It looks like the first of these new PT-series motherboards will employ VT8237. However, the VT8251 should follow shortly and indeed, our reference samples both feature the updated south bridge.

VIA's latest I/O controller also includes PCI Express connectivity through two single-lane pathways. There is a pair of IDE interfaces, accommodating up to four ATA133 devices, and an integrated Serial ATA controller boasting four ports. The SATA implementation supports the second-generation 300 MBps standard as well as NCQ and port multiplication. Previously, each SATA port allowed a connection to one hard drive only. Port multiplier devices will make it possible to attach several drives to each port, better utilizing the copious data ceiling enabled by SATA II. The storage package is rounded out by RAID 0, 1, 0+1, and 5 support through the SATA channels.

Like its predecessor, VT8251 still offers eight USB 2.0 ports and ordinary Fast Ethernet, rather than Gigabit. And while it may be disappointing that VIA didn't beef up the networking feature set to match NVIDIA's the PT894 does boast HD Audio compliance thanks to its advanced Envy24 controller. Naturally, each motherboard manufacturer will have to evaluate the utility of high-def audio on a board-by-board basis, but VIA at least enables the capability, drawing even with Intel in that regard.

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